1. Technical Field
The present disclosure relates to an auxiliary light projection apparatus, a flash apparatus, and a photographing system.
2. Description of the Related Art
A known auxiliary light projection system is mounted to or built in a camera having an auto-focus detection device, projects a focus detection pattern as an auxiliary light on a subject, and allows the auto-focus detection device to detect the focus detection pattern reflected from the subject. The focus detection pattern is compact in a region near the center of a photographing screen, and is sparse in the remaining region of the photographing screen. Accordingly, even if a wide-angle lens or a telephoto lens is used, the relationship between an auto-focusing area and the focus detection pattern can be adjusted so that the auto-focus detection may be performed accurately. However, since the auxiliary light projection apparatus is placed away from a photographing lens, movement of the auto-focusing area to be within the focus detection pattern depends on a focus distance. In the known system, when the focus distance is large, the center of the auto-focusing area deviates from the compact region of the focus detection pattern. As a result, sufficient accuracy of the auto-focus detection by the auxiliary light projection may not be obtainable.